me in below Snyder's Bluff, between the city and
Haines's Bluff. The works at the latter point had been abandoned the
evening before on the approach of the army; a small party only being
left to destroy or remove whatever they could. Upon the appearance of
the troops the admiral sent up a force of gunboats under
Lieutenant-Commander K.R. Breese, whereupon the party ran off, leaving
everything in good order. The works mounted fourteen heavy guns,
VIII-and X-inch smooth-bores, and VII1/2-inch rifles; the carriages of
these were burned, as were the Confederate encampments, and the
magazines blown up. Porter now received letters from Grant, Sherman,
and Steele, informing him of the entire success of the campaign in the
rear of Vicksburg, and asking that provisions might be sent up, the
army having lived off the country almost entirely during a fortnight
of constant marching and fighting. Lieutenant-Commander J.G. Walker
in the De Kalb was sent up to Yazoo City with sufficient force to
destroy the enemy's property which he might find, and the gunboats
below Vicksburg were moved up to fire on the hill batteries, an
annoyance to the garrison which they kept up off and on during the
night. On the 19th six mortar-boats were got into position, with
orders to fire night and day as rapidly as possible.

Grant, having completed the investment of Vicksburg, sent word on the
evening of the 21st that he intended to make a general assault upon
the enemy's works at 10 A.M. the following day, and asked that the
fleet might shell the batteries from 9.30 to 10.30. Porter complied by
keeping up his mortar fire all night and sending up the gunboats to
shell the water batteries, and other places where he thought the enemy
might find rest. At 7 A.M. the next day the Mound City, followed at
eight by the Benton, Tuscumbia, and Carondelot, moved up abreast the
lower end of the canal, opening upon the hill batteries; then they
attacked the water batteries, the duel between them and the ships at a
range of four hundred and fifty yards being maintained incessantly for
two hours. The Tuscumbia proved, as before, too weak to withstand such
close action and had to drop down. The admiral wrote that this was the
hottest fire that the gunboats had yet endured, but the water
batteries having little elevation, the ships contended on more even
terms than at Grand Gulf, and fighting bows on, received little
damage.

The fire was maintained for an hour longer